The invention relates to pressure gauges, and more particularly relates to a combination in-line pressure sensor and portable gauge head. The portable gauge head, during a given use, is releasably coupled to the in-line sensor to detect a message signal given off by the in-line sensor and convert that message signal into a visible indication of the pressure sensed by the in-line sensor. After a given use, the portable gauge head is decoupled from the in-line sensor and is transported elsewhere either for use with another in-line sensor at a different location or else for storage between uses.
An example utility for the combination in-line pressure sensor and portable gauge head in accordance with the invention includes, without limitation, a car refrigerant system for the passenger air conditioning. The installation in a car refrigerant system would comprise placement of one in-line pressure sensor at the low-pressure test-and-service valve-fitting and placement of another in-line pressure sensor at the high-pressure test-and-service valve-fitting of the refrigerant circuit of the car air conditioning system.
Accordingly, an inventive aspect here includes that pressure measurements can be taken at either the low- or the high-pressure test-and-service fitting without risking leaking any refrigerant at all to the atmosphere. The in-line pressure sensors remain semi-permanently installed in the refrigerant circuit. The portable gauge head is only brought to the scene whenever a user wishes to take a pressure measurement. The same gauge head can be used at either the high or the low side of the test-and-service valve-fittings. Indeed, the same gauge head can be used repetitively over and over to service any car that is outfitted with a pair of in-line sensors in accordance with the invention.
Thus it is another inventive aspect that a user of the combination in-line pressure sensor(s) and portable gauge head in accordance with the invention, is enabled to diagnose a car's refrigerant circuit without opening the circuit. The user need only possess a single gauge head to diagnose one car after another if the successive cars are configured with the in-line sensors in accordance with the invention.
A number of additional features and objects will be apparent in connection with the following discussion of preferred embodiments and examples.